Height-adjustable coupling assembly with load-bearing pin for use with a gooseneck trailer

ABSTRACT

Disclosed herein is a coupling assembly for use with a gooseneck trailer. The coupling assembly comprises a height-adjustment device and a coupler mechanism. The coupling assembly further comprises a locking assembly and a pair of friction fit assemblies. The height-adjustment device within the coupling assembly uses a load-bearing pin to concurrently and/or simultaneously perform two functions, namely permitting adjustablility of the coupling assembly and bearing all, or substantially all, of a vertical load (i.e., withstanding a shear force) provided by an attached gooseneck trailer, any trailer accessories, and any trailer contents. Because the load-bearing pin bears all, or substantially all, of the vertical load by resisting the shear force, conventional reliance upon a friction force to bear the vertical load is substantially eliminated. A tongue on the gooseneck trailer connects the gooseneck trailer to the coupling assembly and the coupler mechanism on the coupling assembly secures a ball mount on a towing vehicle to the coupling assembly. As such, the gooseneck trailer and the towing vehicle can be coupled and uncoupled. The locking assembly on the coupling assembly alternatively locks and unlocks the coupler mechanism. The friction fit assemblies on the coupling assembly inhibit relative side-to-side movement between an inner and outer member within the coupling assembly.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of the filing date of U.S.application Ser. No. 10/097,885, filed on Mar. 14, 2002, pending, whichclaims the benefit of U.S. provisional application Serial No.60/318,227, filed on Sep. 7, 2001, expired.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention generally relates to a coupling assemblyfor securing a trailer to a 10′ towing vehicle. In one aspect, thecoupling assembly comprises a coupler mechanism and a height-adjustmentdevice, the height-adjustment device utilizing apertured couplingmembers and a load-bearing pin, the load-bearing pin being selectivelyinsertable within the apertures in the coupling members to permit heightadjustment of the coupler and to accept a vertical load delivered to thecoupling assembly by the trailer.

[0004] 2. Description of the Related Art

[0005] A typical trailer, such as a gooseneck trailer, comprises atrailer mount assembly and an attached coupling assembly. The couplingassembly is configured to receive a ball mount secured to a bed of atowing vehicle. When the coupling assembly receives and secures the ballmount, the towing vehicle is “coupled” to the trailer. When coupled, thetowing vehicle can transport the trailer. When no longer needed, thetrailer can be “uncoupled” from the towing vehicle by releasing thecoupling assembly. When released, the ball mount is unsecured anddischarged from the within the coupling assembly. Thereafter, the towingvehicle can proceed unencumbered by the trailer. The process ofcoupling, and uncoupling, can be repeatedly performed.

[0006] Many conventional coupling assemblies include inner and outertubular members associated with a variety of bolts, pins, and/or otherconnectors [hereinafter bolt]. The tubes are disposed in a telescopicmating, engagement. Therefore, the combined height of the tubes can beincreased or decreased by sliding the tubes relative to each other. Thebolt secured to the outer tube typically extends through an aperture inthe outer tube and contacts the sliding surface of the inner tube. Thebolt can thereafter generate friction at the inner tube to maintain thetubes at a desired, combined height. The friction supplied by the boltpermits the coupling assembly to bear a vertical load exerted by atrailer and its contents. Thus, conventional, adjustable couplingassemblies permit a trailer to be leveled and then secured for suitabletowing using the force of friction generated by a bolt or like device.Unfortunately, the use of friction in a coupling assembly may permitslippage between the tubes if the force of friction should waver or beovercome.

[0007] In U.S. Pat. No. 6,234,509 (Lara), telescopic, outer and innertubes are employed in a coupling assembly. As illustrated in FIG. 6, anadjusting nut is secured to the outer tube proximate an outer tubeaperture. The adjusting nut receives a corresponding adjusting bolt thatcan advance or retreat within the adjusting nut and outer tube aperturewhen rotated. When the desired height of the combined inner and outertubes is achieved, the adjusting bolt is rotated until a distal end ofthe adjusting bolt is biased against the inner tube. With the distal endof the adjusting bolt lodged against the inner tube, friction is createdbetween the distal end of the adjusting bolt and the inner tube. Theadjusting bolt maintains the desired height of the combined inner andouter tubes and bears a portion of the vertical load provided by atrailer attached to the coupling assembly. Friction, and friction alone,permits the adjusting bolt in the coupling assembly to perform these twofunctions.

[0008] In another embodiment of U.S. Pat. No. 6,234,509 (Lara), the useof a plunger pin assembly in combination with an adjusting bolt and nutis disclosed. As illustrated in FIGS. 4 and 5, the plunger pin assemblycomprises a plunger pin (i.e., a non-threaded bolt) and a compressionspring biasing the plunger pin. The plunger pin assembly is welded tothe outer tube proximate an outer tube aperture. The inner tube containsa single column of inner tube apertures. When the outer tube apertureslidably aligns with one of the inner tube apertures, the plunger pin isreleased and inserted through the outer aperture as well as one of theinner tube apertures. Thereafter, the adjusting bolt is rotated until adistal end of the adjusting bolt is biased against the inner tube. Theplunger pin, in combination with the adjusting bolt, maintains thedesired height of the combined inner and outer tubes and bears thevertical load provided by the trailer attached to the coupling assembly.Therefore, friction and a shear withstanding force, in combination,allow the coupling assembly to provide height adjustment as well as bearthe vertical load of the trailer and its contents. As such, friction isstill being relied upon to assist in maintaining coupling assemblyheight.

[0009] While the above coupling assemblies very capably permit towing ofa trailer, an improved coupling assembly would be desirable.

SUMMARY OF THE INVENTION

[0010] In one aspect, the invention provides a coupling assembly for usewith a trailer such as a gooseneck trailer. The coupling assemblycomprises a height-adjustment device and a coupler mechanism.

[0011] The height-adjustment device includes an inner member, an outermember, and a load-bearing pin. The inner member has opposing innermember aperture pairs while the outer member has an opposing outermember aperture pair. The outer member telescopically, slidably receivesthe inner member such that the inner member can be height adjusted withrespect to the outer member. The load-bearing pin is selectivelyinsertable through one of the opposing inner member aperture pairs andthe opposing outer aperture pair. In one embodiment, the inner memberand the outer member can be elongate members that contain pairs ofapertures that are circumferentially aligned.

[0012] The coupler mechanism is secured to the height-adjustment deviceand engageable to a mount secured to a towing vehicle. The load-bearingpin can bear substantially all of a vertical load exerted upon thecoupling assembly. In one embodiment, the load-bearing pin can bear anyvertical load exerted upon the coupling assembly.

[0013] The coupling assembly can include a friction fit assembly that isemployed to maintain co-axial alignment of the inner member and theouter member. The friction fit assembly and the load-bearing pin can belongitudinally disposed along the outer member at approximately the sameheight. The friction fit assembly can include a fixed nut, a lock nut,and an adjustment bolt.

[0014] The coupling assembly can also contain a locking assembly toalternatively ensure securement and permit release of the mount withinthe coupler mechanism. The locking assembly can be assembled from alocking pin, a locking pin spring, a locking pin handle, and a lockingpin cover.

[0015] A tongue on the trailer can connect the trailer to the couplingassembly. Further, the coupler mechanism on the coupling assembly cansecure the mount on the towing vehicle to the coupling assembly.

[0016] In one embodiment, the load-bearing pin can be angled proximateone end and contain a load-bearing pin aperture proximate another end. Acotter pin can be securable within the load-bearing pin aperture tosecure the load-bearing pin within the coupling assembly.

[0017] The inner member can define an inner member height and the outermember can define an outer member height. Therefore, when the innermember height and the outer member height are summed, a device height isdefined. The device height can be adjusted to level the trailer withrespect to a towing vehicle, the gooseneck trailer, or a combination ofthe towing vehicle and the gooseneck trailer.

[0018] In another aspect, the invention provides a system for adjustingcoupling assembly height. The system comprises a coupling assembly,which contains a height-adjustment device and a coupler mechanism, and agooseneck trailer, which contains a tongue connecting the goosenecktrailer to the coupling assembly. The system uses the height-adjustmentdevice such that a load-bearing pin is securable within one of opposinginner member aperture pairs and a opposing outer member aperture pair toadjust the coupling assembly height. The load-bearing pin can also bearsubstantially all of a vertical load exerted upon the coupling assembly.

[0019] The system can further include the towing vehicle and the couplermechanism. The coupler mechanism can be releasably engaged to the mountsecured to the towing vehicle. The coupler mechanism can alsoalternatively permit coupling and uncoupling of the gooseneck trailer toand from the towing vehicle.

[0020] In yet another aspect, the invention provides a method ofleveling a trailer. The method can comprise initially providing acoupler mechanism and a height adjustment device. The height adjustmentdevice can include an inner member, which has opposing inner memberaperture pairs and defines an inner member height, and an outer member,which has an opposing outer member aperture pair and defines an outermember height. The outer member telescopically, slidably receives theinner member. The height-adjustment device also includes a load-bearingpin that can be selectively insertable through one of the opposing innermember aperture pairs and the opposing outer member aperture pair.

[0021] The inner member and the outer member can be adjusted relative toeach other such that a desired height is achieved and a channel isformed proximate the desired height. Thereafter, the load-bearing pincan be inserted within the channel formed by the adjusted members suchthat the load-bearing pin bears substantially all of a vertical loadprovided by the trailer while maintaining the desired height of thetrailer. This can ensure that the trailer is leveled. The method canfurther comprise securably receiving a mount within the couplermechanism where the mount is secured to a towing vehicle.

[0022] In one embodiment, the method can include providing a frictionfit assembly for promoting co-axial alignment of the inner member andthe outer member. Further, the method can also include providing alocking assembly for preventing undesirable disengagement of a mountsecurably received within the coupler mechanism. In one embodiment, thelocking assembly includes a locking pin such that the locking pin can bemanually manipulatable to alternatively couple and uncouple the mountand the coupler mechanism.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Embodiments of the invention are disclosed with reference to theaccompanying drawings and are for illustrative purposes only. Theinvention is not limited in its application to the details ofconstruction or the arrangement of the components illustrated in thedrawings. The invention is capable of other embodiments or of beingpracticed or carried out in other various ways. Like reference numeralsare used to indicate like components.

[0024]FIG. 1 illustrates a side, elevational view of a trailer employingan embodiment of a coupling assembly, according to one aspect of theinvention, and secured to a towing vehicle.

[0025]FIG. 2 illustrates a side, elevational view of the couplingassembly of FIG. 1.

[0026]FIG. 3 illustrates a side, elevational view of the couplingassembly of FIG. 2 rotated ninety degrees about axis A.

[0027]FIG. 4 illustrates a top, cross-sectional view, taken along lines4-4 of FIG. 2 of a height-adjustment device and a friction fit assembly.

[0028]FIG. 5 illustrates a side, cross-sectional view, taken along line5-5 of FIG. 4, of the height-adjustment device.

[0029]FIG. 6 illustrates a top, plan view of the load-bearing pin andcotter pin used in the height-adjustment device of FIG. 5.

[0030]FIG. 7 illustrates a side, elevational view of a trailer employingthe height-adjustment device of FIG. 5 (within the coupling assembly ofFIG. 2) to control trailer pitch.

[0031]FIG. 8 illustrates a side, elevational view of a coupler mechanismwithin a lower portion of the coupling assembly of FIG. 2.

[0032]FIG. 9 illustrates a top, cross-sectional view, taken along line9-9, of the lower portion of the coupling assembly of FIG. 8 with a lockplate shown in the open position.

[0033]FIG. 9A illustrates a top, cross-sectional view, taken along line9-9, of the lower portion of the coupling assembly of FIG. 8 with thelock plate shown in the closed position.

[0034]FIG. 10 illustrates a perspective view of another embodiment of aheight-adjustable coupling assembly.

[0035]FIG. 11 illustrates a top, cross-sectional view, taken along lines11-11 of FIG. 10 showing another embodiment of a height-adjustmentdevice having a plurality of friction fit assemblies.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] In FIG. 1, towing vehicle 2, trailer 4, and trailer mountassembly 6 are illustrated. Towing vehicle 2 comprises a rear axle 8 anda towing vehicle bed 10, the bed having bed aperture 12 disposedtherein. Trailer 4 can comprise any conventional trailer fortransporting cargo and the like and defines trailer end area 14. Trailermount assembly 6 comprises first tongue end 16, second tongue end 18,and tongue 20 disposed between the first and second tongue ends. In theembodiment shown, tongue 20 comprises a gooseneck-shaped tongue and,therefore, trailer 4 is known as a gooseneck trailer. Tongue 20 canextend over towing vehicle bed 10 such that second tongue end 18 isvertically disposed above rear axle 8 of towing vehicle 2. Directionalarrow 22 indicates the direction of a vertical load (and resultant shearforce) created by trailer 4, any trailer accessories (e.g., tongue 20),and any trailer contents. Trailer 4 is secured to first tongue end 16 attrailer end area 14, typically by welds 24 or other conventional means.Also, second tongue end 18 is secured, typically by welds 24 or otherconventional means, to coupling assembly 26.

[0037] As illustrated in FIG. 2, coupling assembly 26 comprisesheight-adjustment device 28 and coupler mechanism 30. Optionally,coupling assembly 26 further comprises locking assembly 32 and frictionfit assembly 34. In preferred embodiments, height-adjustment device 28is disposed at an upper portion 36 of coupling assembly 26. FIG. 3depicts coupling assembly 26 of FIG. 2 rotated ninety degrees about axisA. FIGS. 2 and 3, in combination, illustrate the various devices,mechanisms, and assemblies relative to each other in preferredembodiments.

[0038] In FIG. 4, a top, cross-sectional view of coupling assembly 26,taken along line 4-4 of FIG. 2, details height-adjustment device 28 andfriction fit assembly 34. As shown, height-adjustment device 28comprises load-bearing pin 38, inner member 40, and outer member 42.Inner member 40 defines inner member periphery 44, inner member firstsurface 46, and inner member second surface 48.

[0039] In FIG. 5, a side, cross-sectional view, taken along line 5-5 ofFIG. 4, illustrates the interaction between inner member 40 and outermember 42. As shown, inner member 40 includes opposing inner memberaperture pairs 50. Each aperture 52 within opposing inner memberaperture pairs 50 extends from inner member first surface 46 to innermember second surface 48. Opposing inner member aperture pairs 50 arelongitudinally spaced over all, or a portion, of inner member height 54and circumferentially aligned about inner member periphery 44 (FIG. 4).While FIG. 5 illustrates five pairs 50 of apertures 52, the number ofpairs employed can be varied to convenience.

[0040] Referring back to FIG. 4, outer member 42 extends around, and isin telescopic, sliding engagement with inner member 40. Outer member 42defines outer member periphery 56, outer member first surface 58, andouter member second surface 60.

[0041] As shown in FIG. 5, outer member 42 includes opposing outermember aperture pair 62. Each aperture 64 within opposing outer memberaperture pair 62 extends from outer member first surface 58 to outermember second surface 60. Opposing outer member aperture pair 62 iscircumferentially-aligned about outer member periphery 56 to correspondto the circumferential alignment of opposing inner member aperture pairs50 about inner member periphery 44. Outer member 42 defines outer memberheight 66.

[0042] The telescopic, sliding inner and outer members 40, 42 areco-axially aligned about axis A, as shown in FIGS. 4 and 5, such thatthe members exhibit a mating engagement. Peripheries 44, 56 (orcorresponding cross-sections) of both inner member 40 and outer member42 can comprise a multitude of shapes, for example, circular, square,rectangular, and the like. In one embodiment, inner member 40 and outermember 42 comprise hollow, elongate members (e.g., tubes). In apreferred embodiment, the elongate members are tubular.

[0043] When added together, inner member and outer member heights 54, 66define device height 68 (FIG. 5). As members 40, 42 are telescopically,slidably manipulated with respect to each other, device height 68 canincrease or decrease. As device height 68 changes, one of opposing innermember aperture pairs 50 can align with opposing outer member aperturepair 62 to form channel 70 through height-adjustment device 28 and,therefore, coupling assembly 26. Channel 70, when formed, is capable ofreceiving load-bearing pin 38.

[0044] To operate height-adjustment device 28, and therefore couplingassembly 26, a desired device height is determined. Thereafter, members40, 42 are slidably adjusted relative to each other until the desireddevice height is achieved. Since inner member 40 comprises a pluralityof opposing inner member aperture pairs 50 spaced along inner memberheight 54, channel 70 can be formed at (or very near) the desired deviceheight. With channel 70 formed at or near the desired device height,load-bearing pin 38 is inserted into the channel. As a result,load-bearing pin 38 occupies one of opposing inner member aperture pairs50 and occupies opposing outer member aperture pair 62. Should a newdesired height be determined, load-bearing pin 38 can be removed,members 40, 42 re-adjusted, and the load-bearing pin re-inserted.

[0045] When occupying channel 70, load-bearing pin 38 can maintain thedesired height of the coupling assembly 26 and can concurrently and/orsimultaneously bear the vertical load (i.e., withstand the shear force)generated by the attached trailer, any trailer accessories, and anytrailer contents.

[0046] In one embodiment, load-bearing pin 38 can maintain the desiredheight of the coupling assembly 26 and concurrently bear all, orsubstantially all, of the vertical load (i.e., withstand the shearforce) of the attached trailer, trailer accessories, and trailercontents. As used herein, the term substantially all is defined asapproximately ninety-five percent (95%) of the vertical load.

[0047] Thus, load-bearing pin 38 permits adjustablility ofheight-adjustment device 28, and therefore coupling assembly 26, whilebearing the vertical load (i.e., withstanding the shear force) suppliedby the attached trailer, any trailer accessories, and any trailercontents. These two functions are simultaneously and/or concurrentlyperformed without relying on friction.

[0048] In a preferred embodiment, as shown in FIG. 6, load-bearing pin38 comprises a solid, elongate member having load-bearing pin aperture74 proximate a first load-bearing pin end 76. Load-bearing pin aperture74 extends laterally, and entirely through, opposing sides ofload-bearing pin 38. Load-bearing pin aperture 74 is designed andconfigured to receive a cotter pin 72, a hair pin, or other likesecuring device. As illustrated in FIG. 6, load-bearing pin 38 can betapered at first load-bearing pin end 76 and angled proximate secondload-bearing pin end 78. Load-bearing pin 38 can be constructed ofsteel, or other like material, and is designed to withstand at leastabout thirty-two thousand five hundred pounds (32,500 lbs.) of shearforce applied transverse (i.e., perpendicular) to axis B. In preferredembodiments, load-bearing pin is capable of withstanding at least aboutthirty-nine thousand pounds (39,000 lbs.) of shear force appliedtransverse (i.e., perpendicular) to axis B. In more preferredembodiments, load-bearing pin is capable of withstanding at least aboutfifty thousand pounds (50,000 lbs.) of shear force applied transverse(i.e., perpendicular) to axis B.

[0049] Referring to FIG. 7, adjustment of device height 68 (FIG. 5)permits angle 80, representing trailer pitch or level, to be customized.This can be highly desirable if bed height 82 above road surface 84 isnot constant. For example, bed height 82 can vary with different towingvehicles 2, as trailer 4 endures variable loading conditions, and thelike. In preferred embodiments, height-adjustment device 28, andtherefore coupling assembly 26, is manipulated such that angle 80comprises approximately ninety degrees. This permits trailer 4 to beapproximately horizontal with respect to towing vehicle 2 and roadsurface 84.

[0050] In FIG. 8, a lower portion 86 of coupling assembly 26 detailscoupler mechanism 30. Coupler mechanism 30 comprises stationary plate88, lock plate 90, pivot pin 92, retainer bracket 94, lock pin 96, andspacers 98.

[0051] Stationary plate 88 comprises concave cavity 100, flange 102,first stationary plate aperture 104, and second stationary plateaperture 106. Stationary plate 88 can also comprise retainer bracket 94secured to top stationary plate surface 122 proximate lock plateassembly end 124, typically by welds 24. Retainer bracket 94 comprisesretaining plate aperture 95.

[0052] Concave cavity 100 extends upwardly into inner member 40 and isconfigured to receive mount 108 (e.g., a ball mount). Mount 108 can besecured within bed aperture 12 disposed in towing vehicle bed 10 oftowing vehicle 2 (FIG. 1). Flange 102 provides a locale for inner member40 to be secured to stationary plate 88, typically by welds 24.Resultantly, height-adjustment device 28 is secured to coupler mechanism30, to form coupling assembly 26, and inner member 40 generally extendsvertically, upwardly from stationary plate 88. Inner member 40 can besolid, or substantially solid, so long as mount 108 can still bereceived in concave cavity 100 of stationary plate 88.

[0053] Referring to FIGS. 8, 9, and 9A, lock plate 90 comprises mountaperture 110, first lock plate aperture 112, a locked-open aperture 114,and a locked-closed aperture 116. Mount aperture 110 is configured toreceive and selectively secure mount 108. As shown in FIG. 8, pivot pin92 occupies first stationary plate aperture 104, one of spacer aperture99, and first lock plate aperture 112.

[0054] Again referring to FIG. 8, lock pin 96 occupies retaining plateaperture 95, second stationary plate aperture 106, and another one ofspacer aperture 99. Retaining plate aperture 95 functions to preventlock pin 96 from losing alignment with second stationary plate aperture106 disposed beneath locking assembly 32. Lock pin 96 next alternativelyoccupies either locked-open aperture 114 or locked-closed apertures 116,as highlighted in FIGS. 9 and 9A, to secure mount 108 within couplingassembly 26. FIG. 9 represents a top, cross-sectional view, taken alongline 9-9, of the coupler mechanism 30 from FIG. 4. In FIG. 9, stationaryplate 88 and lock plate 90 are aligned and therefore receive mount 108within coupler mechanism 30. As shown, lock pin 96 is disposed withinlocked-open aperture 114. Thus, lock plate 90 is secured, with respectto stationary plate 88, in an open position.

[0055] With mount 108 received in coupler mechanism 30, lock pin 96 isslid upwardly and removed from locked-open aperture 114. Lock plate 90can then be rotated about pivot pin 92, with respect to stationary plate88, causing the lock plate and the stationary plate to become offset, asillustrated in FIG. 9A. When the two plates 88, 90 are offset, mountaperture 110 is effectively constricted. As shown in FIG. 9A, lock pin96 is then released and inserted within locked-closed aperture 116.Thus, lock plate 90 is secured, with respect to stationary plate 88, ina locked position. In the locked position, mount 108 is retained withincoupler mechanism 30 and, correspondingly, coupling assembly 26. To onceagain release mount 108 from coupler mechanism 30, the above-describedmethod is repeated in reverse order.

[0056] Conventional coupler mechanisms, coupling assemblies, and methodsof using the same, are detailed in U.S. Pat. Nos. 5,382,109 and6,234,509, the disclosures of which are incorporated herein by thisreference.

[0057] In FIGS. 3 and 8, a preferred embodiment of locking assembly 32is shown. Locking assembly 32 comprises lock pin 96, guide 124, spring126, and cover 128. In FIG. 8, locking assembly 32, with partiallycut-away cover 128, is illustrated in detail. Guide 124 is attached toinner member 40, typically by one or more welds (not shown), thussecuring locking assembly 32 to coupling assembly 26. As shown, lockingpin 96 is slidably secured within guide 124 to permit vertical actuationof the locking pin. In preferred embodiments, locking pin 96 comprises a“D-shaped” handle 130, as illustrated in FIG. 8, to assist manualbiasing of locking assembly 32. With lock plate 90 secured courtesy oflocking assembly 32, coupling assembly 26, and therefore trailer 4, areprevented from undesirably disengaging from mount 108, and thereforetowing vehicle 2.

[0058] In FIG. 4, a cross-section of friction fit assembly 34 is shown.Friction fit assembly 34 comprises adjustment bolt 132, fixed nut 134,and lock nut 136, each of which is threaded in preferred embodiments.Fixed nut 134 can be secured, typically by one or more welds 24, toouter member 42 proximate adjustment bolt aperture 138. Fixed nut 134receives adjustment bolt 132 and, as the adjustment bolt is rotated,adjustment bolt end 140 travels through adjustment bolt aperture 138 inouter member 42 and is moved closer to, or farther away from, innermember 40 depending on the direction of rotation of the adjustment bolt.In a preferred embodiment, adjustment bolt 132 is rotated clockwise tobias adjustment bolt end 140 against inner member first surface 48. Onceadjustment bolt end 140 is biased against inner member first surface 48,lock nut 136 can be rotated such that the lock nut is secured againstfixed nut 134. Friction fit assembly 34 inhibits relative side-to-sidemovement between inner and outer members 40, 42. In other words,friction fit assembly encourages both inner and outer members 40, 42 toremain co-axially aligned about axis A. In preferred embodiments,friction fit assembly 34 does not carry a significant vertical load(i.e., withstand a significant shear force) supplied by trailer 4,trailer accessories, and trailer contents, even though the friction fitassembly may have the ability to do so.

[0059]FIG. 10 illustrates a perspective view of another embodiment of aheight-adjustable coupling assembly. A coupling assembly 200 is shown.Coupling assembly 200 includes a height-adjustment device 202 and acoupling mechanism 204. The height adjustment device 202 comprises: aninner member 206 comprising opposing inner member aperture pairs 208(the apertures on the reverse side not shown). The device 202 furtherincludes an outer member 210 comprising an opposing outer memberaperture pair 212 (shown with pin 214) inserted therethrough). The outermember telescopically, slidably receives the inner member 206 such thatthe inner member can be height adjusted with respect to the outermember. A load-bearing pin 214 is selectively insertable through one ofthe opposing inner member aperture pairs 208 and the opposing outermember aperture pairs 212 and is used to both position the outer memberwith respect to the inner member and to bear substantially all of avertical load exerted upon the coupling assembly. A first friction fitassembly 216 is in threaded engagement with the outer member 210 tomaintain coaxial alignment between the inner member 206 and the outermember. A second friction fit assembly 218 is disposed above the firstfriction fit assembly 216 in threaded engagement with the outer member210, the second friction fit assembly maintains coaxial alignment of theinner member and the outer member (particularly when the couplingassembly is use). Finally, the coupling assembly includes a couplermechanism 204 secured to the height-adjustment device, the couplermechanism engageable to a mount secured to a towing vehicle (see FIG.1).

[0060]FIG. 11 illustrates a top, cross-sectional view, taken along lines11-11 of FIG. 10 showing another embodiment of a height-adjustmentdevice having a plurality of friction fit assemblies. Referring to FIGS.10 and 11, the first and second friction fit assemblies inhibit relativeside-to-side movement between the inner and outer members. The first andsecond friction fit assemblies promote coaxial alignment of the innerand outer members. The first friction fit assembly 216 includes a bolt220 a that passes through a first friction fit adjustment aperture (seeFIG. 4) in the outer member 210, and the second friction fit assembly218 includes a bolt 220 b that passes through a second friction fitadjustment aperture in the outer member (FIG. 11). In one embodiment,the first and second friction fit adjustment apertures are substantiallythe same size. In one embodiment, the first and second friction fitadjustment apertures are vertically aligned along the outer member asshown. In one embodiment, the opposing outer member aperture pairdefines a height adjustment plane 222 and the first and second frictionfit adjustment apertures define a friction fit assembly plane 224, suchthat the height adjustment and friction fit assembly planes areperpendicular to each other. In one embodiment, the first and secondfriction fit assemblies do not carry a significant portion of thevertical load exerted upon the coupling assembly. In one embodiment, thefirst and second friction fit assemblies are not used to position arelative height of the outer member with respect to the inner member.

[0061] In one embodiment, the opposing outer member aperture pair 212(with pin 214 therethrough) and one of the first and second friction fitassembly adjustment apertures 215 defines an arc angle Ψ or Ω of orabout 90 degrees.

[0062] Despite any methods being outlined in a step-by-step sequence,the completion of acts or steps in a particular chronological order isnot mandatory. Further, modification, rearrangement, combination,reordering, or the like, of acts or steps is contemplated and consideredwithin the scope of the description and claims.

[0063] While the present invention has been described in terms of thepreferred embodiment, it is recognized that equivalents, alternatives,and modifications, aside from those expressly stated, are possible andwithin the scope of the appending claims.

What is claimed is:
 1. A coupling assembly for use with a trailer, thecoupling assembly comprising: a height-adjustment device comprising: aninner member comprising opposing inner member aperture pairs; an outermember comprising an opposing outer member aperture pair, the outermember telescopically, slidably receiving the inner member such that theinner member can be height adjusted with respect to the outer member;and a load-bearing pin, the load-bearing pin selectively insertablethrough one of the opposing inner member aperture pairs and the opposingouter member aperture pairs, and is used to both position the outermember with respect to the inner member and to bear substantially all ofa vertical load exerted upon the coupling assembly; a first friction fitassembly in threaded engagement with the outer member to maintaincoaxial alignment between the inner member and the outer member; and asecond friction fit assembly disposed above the first friction fitassembly in threaded engagement with the outer member, the secondfriction fit assembly to maintain coaxial alignment of the inner memberand the outer member; and a coupler mechanism secured to theheight-adjustment device, the coupler mechanism engageable to a mountsecured to a towing vehicle;
 2. The coupling assembly of claim 1,wherein the first and second friction fit assemblies inhibit relativeside-to-side movement between the inner and outer members.
 3. Thecoupling assembly of claim 1, wherein the first and second friction fitassemblies promote coaxial alignment of the inner and outer members. 4.The coupling assembly of claim 1, wherein the first friction fitassembly includes a bolt that passes through a first friction fitadjustment aperture in the outer member, and the second friction fitassembly includes a bolt that passes through a second friction fitadjustment aperture in the outer member.
 5. The coupling assembly ofclaim 4, wherein the first and second friction fit adjustment aperturesare substantially the same size.
 6. The coupling assembly of claim 4,wherein the first and second friction fit adjustment apertures arevertically aligned along the outer member.
 7. The coupling assembly ofclaim 4, wherein the opposing outer member aperture pair defines aheight adjustment plane and wherein the first and second friction fitadjustment apertures define a friction fit assembly plane, and whereinthe height adjustment and friction fit assembly planes are perpendicularto each other.
 8. The coupling assembly of claim 4 wherein one apertureof the opposing outer member aperture pair and one of the first andsecond friction fit assembly adjustment apertures defines an arc angleof about 90 degrees.
 9. The coupling assembly of claim 1 wherein thefirst and second friction fit assemblies do not carry a significantportion of the vertical load exerted upon the coupling assembly.
 10. Thecoupling assembly of claim 1, wherein the first and second friction fitassemblies are not used to position a relative height of the outermember with respect to the inner member.
 11. A method of leveling atrailer, the method comprising: providing a height adjustment device, aninner member comprising opposing inner member aperture pairs; an outermember comprising an opposing outer member aperture pair, the outermember telescopically, slidably receiving the inner member such that theinner member can be height adjusted with respect to the outer member;and a load-bearing pin, the load-bearing pin selectively insertablethrough one of the opposing inner member aperture pairs and the opposingouter member aperture pairs, and is used to both position the outermember with respect to the inner member and to bear substantially all ofa vertical load exerted upon the coupling assembly; a first friction fitassembly in threaded engagement with the outer member to maintaincoaxial alignment between the inner member and the outer member; and asecond friction fit assembly disposed above the first friction fitassembly in threaded engagement with the outer member, the secondfriction fit assembly to maintain coaxial alignment of the inner memberand the outer member; adjusting the inner member and the outer memberrelative to each other such that a desired height is achieved and achannel is formed proximate the desired height; inserting theload-bearing pin within the channel formed by the adjusted members, theload-bearing pin bearing substantially all of a vertical load providedby the trailer such that the desired height is maintained and thetrailer is leveled; and frictionally fitting the inner member and theouter member with the first and the second friction fit assemblies.